# SPDX-FileCopyrightText: Copyright (c) 2022-2024 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: Apache-2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from typing import List

import tensorrt as trt

from ..._common import default_net
from ..._utils import pad_vocab_size, str_dtype_to_trt
from ...functional import (Tensor, gather_last_token_logits,
                           is_gated_activation, non_gated_version)
from ...layers import (MLP, MOE, Attention, AttentionMaskType, AttentionParams,
                       ColumnLinear, Embedding, GatedMLP, KeyValueCacheParams,
                       LayerNorm, LoraParams, MoeConfig, PositionEmbeddingType,
                       PromptTuningEmbedding)
from ...mapping import Mapping
from ...module import Module, ModuleList
from ...quantization import QuantMode
from ..generation_mixin import GenerationMixin


def MLPFactory(hidden_size,
               ffn_hidden_size,
               hidden_act,
               bias=True,
               dtype=None,
               moe_config: MoeConfig = MoeConfig(),
               tp_group=None,
               tp_size=1,
               tp_rank=0,
               quant_mode=QuantMode(0),
               max_lora_rank=None):
    if moe_config.has_moe():
        return MOE(moe_config,
                   hidden_size,
                   ffn_hidden_size,
                   hidden_act,
                   bias,
                   dtype,
                   tp_group,
                   tp_size,
                   tp_rank,
                   quant_mode=quant_mode,
                   max_lora_rank=max_lora_rank)
    MLPClass = GatedMLP if is_gated_activation(hidden_act) else MLP
    hidden_act = non_gated_version(hidden_act)
    return MLPClass(hidden_size,
                    ffn_hidden_size,
                    hidden_act,
                    bias,
                    dtype,
                    tp_group,
                    tp_size,
                    quant_mode,
                    max_lora_rank=max_lora_rank)


class GPTDecoderLayer(Module):

    def __init__(self,
                 hidden_size,
                 num_attention_heads,
                 max_position_embeddings,
                 num_layers,
                 dtype=None,
                 apply_query_key_layer_scaling=False,
                 attention_mask_type=AttentionMaskType.causal,
                 hidden_act='relu',
                 position_embedding_type=PositionEmbeddingType.learned_absolute,
                 quant_mode=QuantMode(0),
                 rotary_embedding_percentage=1.0,
                 rotary_base=10000.0,
                 rotary_scaling=None,
                 inter_size=None,
                 bias=True,
                 num_kv_heads=None,
                 moe_config: MoeConfig = MoeConfig(),
                 use_auto_parallel=False,
                 tp_group=None,
                 tp_size=1,
                 tp_rank=0,
                 max_lora_rank=None):
        super().__init__()
        self.hidden_size = hidden_size
        self.num_attention_heads = num_attention_heads
        self.max_position_embeddings = max_position_embeddings
        self.num_layers = num_layers
        self.dtype = dtype
        self.apply_query_key_layer_scaling = apply_query_key_layer_scaling
        self.attention_mask_type = attention_mask_type
        self.hidden_act = hidden_act
        self.position_embedding_type = position_embedding_type
        self.tp_group = tp_group
        self.tp_size = tp_size
        self.input_layernorm = LayerNorm(normalized_shape=hidden_size,
                                         dtype=dtype)

        self.attention = Attention(
            hidden_size,
            num_attention_heads,
            num_kv_heads,
            max_position_embeddings,
            num_layers,
            apply_query_key_layer_scaling,
            dtype=dtype,
            attention_mask_type=attention_mask_type,
            position_embedding_type=position_embedding_type,
            rotary_embedding_percentage=rotary_embedding_percentage,
            rotary_embedding_base=rotary_base,
            rotary_embedding_scaling=rotary_scaling,
            bias=bias,
            tp_group=tp_group,
            tp_size=tp_size,
            use_auto_parallel=use_auto_parallel,
            tp_rank=tp_rank,
            quant_mode=quant_mode,
            max_lora_rank=max_lora_rank)

        if inter_size is None:
            inter_size = hidden_size * 4

        self.mlp = MLPFactory(hidden_size=hidden_size,
                              ffn_hidden_size=inter_size,
                              hidden_act=hidden_act,
                              dtype=dtype,
                              bias=bias,
                              moe_config=moe_config,
                              tp_group=tp_group,
                              tp_size=tp_size,
                              tp_rank=tp_rank,
                              quant_mode=quant_mode,
                              max_lora_rank=max_lora_rank)
        self.post_layernorm = LayerNorm(normalized_shape=hidden_size,
                                        dtype=dtype)

    def forward(self,
                hidden_states: Tensor,
                attention_mask=None,
                use_cache=False,
                kv_cache_params=None,
                attention_params=None,
                lora_layer_params=None):

        assert isinstance(hidden_states, Tensor)

        residual = hidden_states

        hidden_states = self.input_layernorm(hidden_states)

        attention_output = self.attention(hidden_states,
                                          attention_mask=attention_mask,
                                          use_cache=use_cache,
                                          kv_cache_params=kv_cache_params,
                                          attention_params=attention_params,
                                          lora_layer_params=lora_layer_params)

        if use_cache:
            attention_output, presents = attention_output

        hidden_states = residual + attention_output

        residual = hidden_states
        hidden_states = self.post_layernorm(hidden_states)

        hidden_states = self.mlp(hidden_states)

        hidden_states = residual + hidden_states

        if use_cache:
            return (hidden_states, presents)
        return hidden_states


class GPTModel(Module):

    def __init__(self,
                 num_layers,
                 num_heads,
                 hidden_size,
                 vocab_size,
                 hidden_act,
                 max_position_embeddings,
                 dtype=None,
                 mapping=Mapping(),
                 use_auto_parallel=False,
                 apply_query_key_layer_scaling=False,
                 position_embedding_type=PositionEmbeddingType.learned_absolute,
                 rotary_embedding_percentage=1.0,
                 rotary_base=10000.0,
                 rotary_scaling=None,
                 inter_size=None,
                 bias=True,
                 quant_mode=QuantMode(0),
                 num_kv_heads=None,
                 use_prompt_tuning=False,
                 use_parallel_embedding=False,
                 embedding_sharding_dim=0,
                 moe_config=MoeConfig(),
                 max_lora_rank=None):
        super().__init__()
        self.mapping = mapping
        self.use_prompt_tuning = use_prompt_tuning
        self.position_embedding_type = position_embedding_type

        EmbeddingCls = PromptTuningEmbedding if use_prompt_tuning else Embedding
        self.vocab_embedding = EmbeddingCls(
            vocab_size,
            hidden_size,
            dtype=dtype,
            tp_size=mapping.tp_size if use_parallel_embedding else 1,
            tp_group=mapping.tp_group if use_parallel_embedding else None,
            sharding_dim=embedding_sharding_dim,
            tp_rank=mapping.tp_rank)
        if position_embedding_type == PositionEmbeddingType.learned_absolute:
            self.position_embedding = Embedding(max_position_embeddings,
                                                hidden_size,
                                                dtype=dtype)

        self.layers = ModuleList([
            GPTDecoderLayer(
                hidden_size=hidden_size,
                num_attention_heads=num_heads,
                max_position_embeddings=max_position_embeddings,
                num_layers=num_layers,
                dtype=dtype,
                apply_query_key_layer_scaling=apply_query_key_layer_scaling,
                attention_mask_type=AttentionMaskType.causal,
                hidden_act=hidden_act,
                position_embedding_type=position_embedding_type,
                rotary_embedding_percentage=rotary_embedding_percentage,
                rotary_base=rotary_base,
                rotary_scaling=rotary_scaling,
                num_kv_heads=num_kv_heads,
                tp_group=mapping.tp_group,
                tp_size=mapping.tp_size,
                tp_rank=mapping.tp_rank,
                use_auto_parallel=use_auto_parallel,
                inter_size=inter_size,
                bias=bias,
                quant_mode=quant_mode,
                moe_config=moe_config,
                max_lora_rank=max_lora_rank,
            ) for i in range(num_layers)
        ])

        self.ln_f = LayerNorm(normalized_shape=hidden_size, dtype=dtype)

    def forward(self,
                input_ids,
                position_ids,
                use_cache=False,
                attention_mask=None,
                kv_cache_params=None,
                attention_params=None,
                prompt_embedding_table=None,
                prompt_tasks=None,
                prompt_vocab_size=None,
                lora_params=None):

        args = [prompt_embedding_table, prompt_tasks, prompt_vocab_size
                ] if self.use_prompt_tuning else []
        hidden_states = self.vocab_embedding(input_ids, *args)
        if self.position_embedding_type == PositionEmbeddingType.learned_absolute:
            hidden_states = hidden_states + self.position_embedding(
                position_ids)

        kv_cache_params.fill_none_tensor_list(len(self.layers))

        if use_cache:
            presents = []

        for layer_idx, (
                layer, past, pointer, host_pointer,
                max_attention_window_size) in enumerate(
                    zip(self.layers, kv_cache_params.past_key_value,
                        kv_cache_params.kv_cache_block_pointers,
                        kv_cache_params.host_kv_cache_block_pointers,
                        kv_cache_params.host_max_attention_window_sizes)):
            lora_layer_params = None
            if lora_params.lora_ranks is not None:
                lora_layer_params = lora_params.get_layer_params(layer_idx)

            hidden_states = layer(
                hidden_states,
                use_cache=use_cache,
                attention_mask=attention_mask,
                kv_cache_params=KeyValueCacheParams(
                    past_key_value=[past],
                    host_past_key_value_lengths=kv_cache_params.
                    host_past_key_value_lengths,
                    host_max_attention_window_sizes=max_attention_window_size,
                    host_sink_token_length=kv_cache_params.
                    host_sink_token_length,
                    kv_cache_block_pointers=[pointer],
                    host_kv_cache_block_pointers=[host_pointer],
                    cache_indirection=kv_cache_params.cache_indirection),
                attention_params=attention_params,
                lora_layer_params=lora_layer_params)

            if use_cache:
                presents.append(hidden_states[1])
                hidden_states = hidden_states[0]

        hidden_states = self.ln_f(hidden_states)

        if use_cache:
            return (hidden_states, tuple(presents))
        return hidden_states


class GPTLMHeadModel(GPTModel, GenerationMixin):

    def __init__(self,
                 num_layers,
                 num_heads,
                 hidden_size,
                 vocab_size,
                 hidden_act,
                 max_position_embeddings,
                 dtype,
                 logits_dtype='float32',
                 mapping=Mapping(),
                 use_auto_parallel=False,
                 apply_query_key_layer_scaling=False,
                 position_embedding_type=PositionEmbeddingType.learned_absolute,
                 rotary_embedding_percentage=1.0,
                 rotary_base=10000.0,
                 rotary_scaling=None,
                 inter_size=None,
                 bias=True,
                 quant_mode=QuantMode(0),
                 num_kv_heads=None,
                 use_prompt_tuning=False,
                 use_parallel_embedding=False,
                 embedding_sharding_dim=0,
                 moe_config=MoeConfig(),
                 share_embedding_table=False,
                 max_lora_rank=None):

        if isinstance(dtype, str):
            self._kv_dtype = str_dtype_to_trt(dtype)
        else:
            assert isinstance(dtype, trt.DataType)
            self._kv_dtype = dtype

        if share_embedding_table and mapping.tp_size > 1:
            if (not use_parallel_embedding) or (use_parallel_embedding and
                                                embedding_sharding_dim == 1):
                raise NotImplementedError(
                    'For multiple-processes cases, sharing the embedding table must set use_parallel_embedding=True and embedding_sharding_dim = 0'
                )

        self._dtype = self._kv_dtype
        self.quant_mode = quant_mode
        if quant_mode.has_int8_kv_cache():
            self._kv_dtype = str_dtype_to_trt('int8')
        elif quant_mode.has_fp8_kv_cache():
            self._kv_dtype = str_dtype_to_trt('fp8')

        if isinstance(logits_dtype, str):
            self._logits_dtype = str_dtype_to_trt(logits_dtype)
        else:
            assert isinstance(logits_dtype, trt.DataType)
            self._logits_dtype = logits_dtype

        self._num_layers = num_layers
        self._num_heads = num_heads
        self._hidden_size = hidden_size
        self._vocab_size = vocab_size
        self._tp_size = mapping.tp_size
        self._num_kv_heads = num_kv_heads if num_kv_heads else num_heads

        super().__init__(
            num_layers=num_layers,
            num_heads=num_heads,
            hidden_size=hidden_size,
            vocab_size=vocab_size,
            hidden_act=hidden_act,
            max_position_embeddings=max_position_embeddings,
            dtype=dtype,
            mapping=mapping,
            use_auto_parallel=use_auto_parallel,
            apply_query_key_layer_scaling=apply_query_key_layer_scaling,
            position_embedding_type=position_embedding_type,
            rotary_embedding_percentage=rotary_embedding_percentage,
            rotary_base=rotary_base,
            rotary_scaling=rotary_scaling,
            inter_size=inter_size,
            bias=bias,
            quant_mode=quant_mode,
            num_kv_heads=num_kv_heads,
            use_prompt_tuning=use_prompt_tuning,
            use_parallel_embedding=use_parallel_embedding,
            embedding_sharding_dim=embedding_sharding_dim,
            moe_config=moe_config,
            max_lora_rank=max_lora_rank,
        )
        vocab_size_padded = pad_vocab_size(vocab_size, mapping.tp_size)

        share_weight = None
        if share_embedding_table:
            share_weight = self.vocab_embedding.weight
        self.lm_head = ColumnLinear(hidden_size,
                                    vocab_size_padded,
                                    bias=False,
                                    dtype=dtype,
                                    tp_group=mapping.tp_group,
                                    tp_size=mapping.tp_size,
                                    gather_output=True,
                                    share_weight=share_weight)

    def forward(self,
                input_ids: Tensor,
                position_ids=None,
                use_cache=False,
                last_token_ids=None,
                attention_mask=None,
                kv_cache_params=None,
                attention_params=None,
                prompt_embedding_table=None,
                prompt_tasks=None,
                prompt_vocab_size=None,
                lora_params=None):

        hidden_states = super().forward(input_ids, position_ids, use_cache,
                                        attention_mask, kv_cache_params,
                                        attention_params,
                                        prompt_embedding_table, prompt_tasks,
                                        prompt_vocab_size, lora_params)

        if use_cache:
            hidden_states, presents = hidden_states

        hidden_states = gather_last_token_logits(
            hidden_states, last_token_ids,
            default_net().plugin_config.remove_input_padding)

        # [batch_size, hidden_size] -> [batch_size, vocab_size]
        lm_logits = self.lm_head(hidden_states)
        lm_logits.mark_output('logits', self._logits_dtype)

        if use_cache:
            if not default_net().plugin_config.paged_kv_cache:
                for i, present in enumerate(presents):
                    present.mark_output(f'present_key_value_{i}',
                                        self._kv_dtype)
            return (lm_logits, presents)

        return lm_logits

    def prepare_inputs(self,
                       max_batch_size,
                       max_input_len,
                       max_seq_len,
                       use_cache,
                       max_beam_width: int = 1,
                       max_num_tokens: int = None,
                       prompt_embedding_table_size: int = 0,
                       gather_context_logits: bool = False,
                       gather_generation_logits: bool = False,
                       max_draft_len: int = 0,
                       lora_target_modules: List[str] = None):
        '''@brief: Prepare inputs Tensors for the model, the given sizes are used to determine the
            ranges of the dimensions of when using TRT dynamic shapes.

            @return: a list contains values which can be fed into the self.forward()
        '''

        # Prepare inputs
        head_size = self._hidden_size // self._num_heads
        num_heads_kv = self._num_kv_heads
        remove_input_padding = default_net().plugin_config.remove_input_padding
        use_gpt_attention_plugin = default_net(
        ).plugin_config.gpt_attention_plugin
        use_gemm_plugin = default_net().plugin_config.gemm_plugin
        paged_kv_cache = default_net().plugin_config.paged_kv_cache
        tokens_per_block = default_net().plugin_config.tokens_per_block
        use_custom_all_reduce = default_net(
        ).plugin_config.use_custom_all_reduce
        use_lora_plugin = default_net().plugin_config.lora_plugin

        model_inputs = self.prepare_basic_inputs(
            max_batch_size=max_batch_size,
            max_beam_width=max_beam_width,
            max_input_len=max_input_len,
            max_seq_len=max_seq_len,
            num_kv_heads=num_heads_kv,
            head_size=head_size,
            num_layers=self._num_layers,
            kv_dtype=self._kv_dtype,
            num_heads=self._num_heads,
            dtype=self._dtype,
            remove_input_padding=remove_input_padding,
            use_gpt_attention_plugin=use_gpt_attention_plugin,
            use_gemm_plugin=use_gemm_plugin,
            use_custom_all_reduce=use_custom_all_reduce,
            paged_kv_cache=paged_kv_cache,
            tokens_per_block=tokens_per_block,
            gather_context_logits=gather_context_logits,
            gather_generation_logits=gather_generation_logits,
            mapping=self.mapping,
            max_num_tokens=max_num_tokens,
            prompt_embedding_table_size=prompt_embedding_table_size,
            use_lora_plugin=use_lora_plugin,
            max_draft_len=max_draft_len,
            lora_target_modules=lora_target_modules)

        return (
            model_inputs['input_ids'],
            model_inputs['position_ids'],
            True,
            model_inputs['last_token_ids'],
            model_inputs['attention_mask'],
            KeyValueCacheParams(
                past_key_value=model_inputs['past_key_value'],
                host_past_key_value_lengths=model_inputs[
                    'host_past_key_value_lengths'],
                host_max_attention_window_sizes=model_inputs[
                    'host_max_attention_window_sizes'],
                host_sink_token_length=model_inputs['host_sink_token_length'],
                kv_cache_block_pointers=model_inputs[
                    'kv_cache_block_pointers_list'],
                host_kv_cache_block_pointers=model_inputs[
                    'host_kv_cache_block_pointers_list'],
                cache_indirection=model_inputs['cache_indirection'],
            ),
            AttentionParams(
                sequence_length=model_inputs['sequence_length'],
                context_lengths=model_inputs['context_lengths'],
                host_context_lengths=model_inputs['host_context_lengths'],
                max_context_length=max_input_len,
                host_request_types=model_inputs['host_request_types']),
            model_inputs['prompt_embedding_table'],
            model_inputs['tasks'],
            model_inputs['prompt_vocab_size'],
            LoraParams(
                model_inputs['lora_ranks'],
                model_inputs['lora_weights_pointers'],
                host_context_lengths=model_inputs['host_context_lengths'],
                max_context_length=max_input_len,
                host_request_types=model_inputs['host_request_types']),
        )
